[ENG-17052][build-tools] Add working_directory input to eas/build function group

[szdziedzic]

Why

To support custom build workflows that check out a repository, create a new Expo app inside it, and then build that app, we need a way to override the working directory for the eas/build function group.

How

Added working_directory as an optional input to the eas/build function group via inputProviders. When provided, it's propagated to all build steps except eas/checkout (which doesn't use workingDirectory - it operates on projectSourceDirectory/projectTargetDirectory directly).

For steps that already define their own relative working directory (e.g. installPods with./ios), the directories are composed using path.join - so working_directory: ./my-app with ./ios results in my-app/ios.

Test plan

Add automated tests.

Test manually with

name: Build

on:
  workflow_dispatch:
    inputs:
      platform:
        description: 'The platform to build for.'
        type: choice
        required: true
        options:
          - android
          - ios
      profile:
        description: 'The build profile to use'
        type: string
        required: false
        default: production
      message:
        description: 'Custom message attached to the build'
        type: string
        required: false

jobs:
  build_ios:
    name: Build iOS
    type: build
    params:
      platform: ${{ inputs.platform }}
      profile: ${{ inputs.profile }}
      message: ${{ inputs.message }}
    env:
      JAVA_HOME: /opt/homebrew/opt/openjdk@17
      ANDROID_HOME: /Users/szdziedzic/Library/Android/sdk
    steps:
      - uses: eas/checkout

      - run: npx create-expo-app@latest local-testing --template blank
        name: Create Expo app in subdirectory

      - run: cd local-testing && npx -y eas-cli@latest init --id 294b6e21-a144-483b-9f94-56ffa25905f4 --non-interactive
        name: Configure EAS project

      - uses: eas/build
        with:
          working_directory: ./local-testing

[linear]

ENG-17052 Add `working_directory` to `eas/build` function group

[szdziedzic]

• [ENG-17052][build-tools] Add working_directory input to eas/build function group #3582 👈 (View in Graphite)
• main

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[Copilot]

Pull request overview

Adds a working_directory input to the eas/build function group so callers can run the group’s steps from a subdirectory (e.g. monorepos), while preserving step-specific directories like ./ios for CocoaPods.

Changes:

• Introduces an optional working_directory input provider on the eas/build function group and propagates it to almost all generated steps.
• Adds helper logic to compose the function-group working directory with step-level working directories (notably Install Pods).
• Adds unit tests validating propagation/composition behavior across iOS/Android variants.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
packages/build-tools/src/steps/functionGroups/build.ts	Adds working_directory input handling and propagates it to generated steps; composes with step-level dirs for iOS pods.
packages/build-tools/src/steps/functionGroups/tests/build.test.ts	New tests covering working directory propagation and composition across platforms/credential modes.

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[github-actions]

✅ Thank you for adding the changelog entry!

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Subscribed to pull request

File Patterns	Mentions
**/*	@douglowder

Generated by CodeMention

[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

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[codecov]

Codecov Report

❌ Patch coverage is 90.00000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 54.43%. Comparing base (c6d4fae) to head (53645d9).

Files with missing lines	Patch %	Lines
...ages/build-tools/src/steps/functionGroups/build.ts	90.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3582      +/-   ##
==========================================
+ Coverage   54.27%   54.43%   +0.16%     
==========================================
  Files         820      820              
  Lines       35055    35063       +8     
  Branches     7260     7262       +2     
==========================================
+ Hits        19024    19084      +60     
+ Misses      15944    15888      -56     
- Partials       87       91       +4     

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